WINNING THE WAR.

Taranaki Daily News, 7 January 1921, Page 7

WINNING THE WAR.

PART PLAYED BY EDISON. SOME WONDERFUL INVENTIONS. HOW HE TRACKED THE U BOATS. Thomas Alva Edison devised no marvellous electric machine to annihilate at one stroke the armies of our enemies, as credulous persons expected, at the outset of the war, that he would do. What Edison did do, however, is set forth by a contributor to Engineering and Contracting (Chicago), and after perusing the account, the reader may not be blamed for adding the name of Edison to those of the numerous persons and organisations who are credited with “winning the war.” Some of Edison’s contributions were: The device ‘for detecting 'subma-* rines by sound from a moving vessel. That for turning a ship quickly at right angles. Collision mats for minimising loss from torpedo attackMethod of camouflaging vessels. Obstruction of torpedoes with nets. The under-water searchlight. Oleum cloud-shells. High-speed signalling with searchlights. Water-penetrating projectiles. Researches on) the zig-zagging of ships. Production of nitrogen gas from the air. A hydrogen-detector for submarines. Protection of observers from smoke stack gas. Device for use in watching for periscopes. Putting out coal-bunker fires-Direction-finder for hostile airplanes. Locating hidden guns by “sound ranging.” And the preservation of submarine

guns from rust. When submarine activity began to play havoc with shipping, the problem of detecting the location of submarines by sound was considered one o r the foremost problems of the day, and in a very short time it was recognised as being perhaps the most difficult one. Mr. Edison gave this problem a large part of his attention, and in the summer and fall of 1917 had reached a fair degree of success in detecting sounds of torpedoes as far as 500 yards distant.

He became convinced that if he could instal on a ship a device that could be ananged so that it would always be from 10ft. to 20ft. ahead of the bo.v of the vessel, and if this device could carry a vibrating diaphragm, it- would not have to contend with the noises of the ship itself. The device succeeded, and boats moving 1700 yards away could be readily heard while the vessel was going full speed. A submarine bell 5$ miles away could also be heard by the operator while a big storm was in progressWith this device there would be no difficulty whatever in hearing a torpedo is very piercing and peculiarly disthis is far beyond the effective distance at which a torpedo can be launched from a submarine. The noise by a torpedo is very jpierc’ng and peculiarly distinctive.

Mr. Edison desired to provide cargoboats with a means of turning the ship very quickly to a right angle course on hearing the launching of a torpedo by liis listening device

Mr. Edison’s plan included the use of four sea anchors, each about Oft. in diameter at the mouth and each attached to a 4in. rope. The plan was t.o fasten the ends of these ropes securely in the bow of the ship and to have the -ca anchors placed at the end of the ropes and midway of the ship. If the observer at the listening device reported a torpedo launched by a submarine at a distance, the signal was given and the four sea anchors were to be immediately released and thrown overboard, anl ke helm thrown hard over bringing the vessel almost to a standstill rapidly tu’nlng her at right angles in her or’gmal course. In a test a ’oadtd vessel 3?sff. in length was turned 90 deg. from her course is 2min lOsec, with an advance of only 200 ft.

Mr. Edison experimented on a plan to enable merchant ships to escape torpedoes by the use of a gun, similar to a trench mortar, from which should be fired an obstruction netting. The plan was that a large number of these nets should be thrown in its path, giving sufficient retardation that it would be stopped or be so delayed ae to miss the ship. One of the problems placed before Mr. Edison was to provide a searchlight to be used under water by submarines. After making a great number of experiments he found that the green line of barium in the arc (light) penetrated •salt water farther than any other he had observed. His last experiments “were with a 60-foot tube filled with sea water, at the end of which sufficient light was transmitted to read print. During the height of enemy submarine activity, Mr. Edison also devised a type of projectile which would enter the water direct without ricochet, and would continue its course without deflection and make a penetrative hitA simple little device for use by lookout men in watching for periscopes in bright sunlight was suggested by Mr. Edison. It consisted of a tapering metallic box l , open at both ends, fitted with a light-excluding eyepiece, and having diaphragms placed at intervals along its inside length. The device was painted in a dead black inside and out, and its construction was very cheap. With it objects could *be discerned in the full light of day that were otherwise invisible. The determination of the location of hidden guns by observing the time intervals between which the sound of their discharge reached several known points was early undertaken by Mr. Edison. Actual tests made by modern guns showed that under varying weather conditions the position of an unknown sound could be located within two per cent., plus or minus, of the measured distance, with a base line not exceeding one-sixth of the iange distance. Under favorable conditions some remarkably close results were obtained. With a base line 1800 f- long (the longest base line used) the gun .has been located over two and a half miles away, within a foot or two of the actual position. One of the problems submitted to Mr Edison was to find some method of preserving submarine guns from rust He made a large number of experiments, and finally found that, if extra fine zinc dust is mixed with" vaseline and smeared over the gun no rust whatever is formed, either in air, or sprayed with sea water. If only plain vaseline was used the polished steal beoaml rutted-